The present invention relates generally to cutting tools and, more particularly, to cutting tools that employ fluid as the cutting element.
In the oil and gas industry, it is often necessary to cut, perforate or separate tubular members downhole. For example, when a drill pipe becomes stuck, the drill string must be severed above the stuck point so that the upper portion can be removed. It is sometimes desirable to sever casing or tubing downhole to make repairs or withdraw the tubing from a well that is being abandoned. Occasionally, the tubing or casing may need to be perforated downhole to improve recovery from a formation. Various cutting devices have been used for these purposes. Chemical cutters may be used, but have temperature and pressure limitations. Mechanical cutters may be used, but have size and strength limitations.
The present invention is directed to a cutting tool. The tool comprises a body formed by a wall and having a longitudinal axis and a fluid conduit. At least one port is formed in the body in fluid communication with the fluid conduit, so that the port is positioned to direct fluid from the fluid conduit through the wall of the body at an angle to the longitudinal axis.
The present invention further comprises a cutting tool assembly. The assembly includes a cutting tool comprising a body formed by a wall and having a first end and a second end. The body has a longitudinal axis and comprises a fluid conduit. At least one port is formed in the body in fluid communication with the fluid conduit, so that the port is positioned to direct fluid from the fluid conduit through the wall of the body at an angle to the longitudinal axis of the body. The assembly further includes a rotational drive system with a first end and a second end. The first end is connectable to a drive source, and the second end is connectable to the first end of the cutting tool.
Still further, the present invention includes a method of cutting a tubular member having a lumen defined by a sidewall with an inner surface. The method comprises directing a jet of fluid from within the lumen of the tubular member at the inner surface of the sidewall in a circumferential motion until the sidewall is at least partially cut.